In the Linux kernel, the following vulnerability has been resolved:
binder: fix async_free_space accounting for empty parcels
In 4.13, commit 74310e06be4d ("android: binder: Move buffer out of area shared with user space")
fixed a kernel structure visibility issue. As part of that patch,
sizeof(void *) was used as the buffer size for 0-length data payloads so
the driver could detect abusive clients sending 0-length asynchronous
transactions to a server by enforcing limits on async_free_size.
Unfortunately, on the "free" side, the accounting of async_free_space
did not add the sizeof(void *) back. The result was that up to 8-bytes of
async_free_space were leaked on every async transaction of 8-bytes or
less. These small transactions are uncommon, so this accounting issue
has gone undetected for several years.
The fix is to use "buffer_size" (the allocated buffer size) instead of
"size" (the logical buffer size) when updating the async_free_space
during the free operation. These are the same except for this
corner case of asynchronous transactions with payloads < 8 bytes.
binder: fix async_free_space accounting for empty parcels
In 4.13, commit 74310e06be4d ("android: binder: Move buffer out of area shared with user space")
fixed a kernel structure visibility issue. As part of that patch,
sizeof(void *) was used as the buffer size for 0-length data payloads so
the driver could detect abusive clients sending 0-length asynchronous
transactions to a server by enforcing limits on async_free_size.
Unfortunately, on the "free" side, the accounting of async_free_space
did not add the sizeof(void *) back. The result was that up to 8-bytes of
async_free_space were leaked on every async transaction of 8-bytes or
less. These small transactions are uncommon, so this accounting issue
has gone undetected for several years.
The fix is to use "buffer_size" (the allocated buffer size) instead of
"size" (the logical buffer size) when updating the async_free_space
during the free operation. These are the same except for this
corner case of asynchronous transactions with payloads < 8 bytes.
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Linux |
|
Configuration 1 [-]
|
No data.
No data.
References
History
Mon, 04 Nov 2024 12:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-04T07:00:39.427Z
Reserved: 2024-02-25T13:45:52.720Z
Link: CVE-2021-46935
Vulnrichment
Updated: 2024-08-04T05:17:43.010Z
NVD
Status : Modified
Published: 2024-02-27T10:15:07.957
Modified: 2024-11-21T06:34:58.220
Link: CVE-2021-46935
Redhat
OpenCVE Enrichment
No data.